ABSTRACT
General-purpose colour cathode ray tube (CRT) monitors are used commonly for image display in personal computer-based picture archiving and communication system (PACS) and telemedicine systems. At present, however, we have not enough information about their performance or reliability for this task. Therefore, we studied the performance of five general-purpose colour CRTs and the changes in their performance in a year. Resolution was measured visually using original digital images. Maximum and minimum luminances were measured at the centre and periphery of the CRTs. Distortion was measured in the centre and periphery using original digital images. All the monitors met their specifications. The inhomogeneity of luminance exceeded 20% and varied across the CRTs. Darker monitors took more time to reach stable luminance levels. The corner brightness seemed to be a good estimator of both performance and distortion in colour monitors.
Subject(s)
Radiographic Image Enhancement/instrumentation , Radiology Information Systems/instrumentation , Humans , Teleradiology/instrumentationABSTRACT
A dual beam laser diode scanning method for an ultrahigh speed laser printer is proposed and its feasibility is tested. Two separate laser beams are scanned simultaneously by one facet of a polygon mirror. By employing this method, power emitted from each laser and the rotation speed of the polygon mirror can be reduced to half, compared with those in single beam scanning systems. Spacing between two lines is compensated for by a sample-and-hold spot control method.
